Diaper bag



FIG. 1 is a perspective view of a diaper bag showing my new design, the strap assembly shown in dotted lines being for illustrative purposes only and not a part of the claimed design;

FIG. 2 is a reduced scale bottom plan view thereof;

FIG. 3 is a rear elevational view thereof;

FIG. 4 is a left side elevational view thereof. 

The ornamental design for a diaper bag, substantially as shown and described. 